Plastic ring and method of making the same



Dec. 16,1947. J EVALT 2,432,870

PLASTIC RING AND METHOD OF MAKING THE SAME Fil'ed Feb. 25, 1944 Patented Dec. 16, 1947 METHOD OF MAKING SAME George J. Evalt, Philadelphia, Pa.

Application February 25, 1944, Serial No. 523,947

PLASTIC RING AND THE 7 Claims.

This invention relates to a plastic ring or loop and to a method of manufacturing the same.

An important object of the invention is a pro- VlsiOn of a permanently sealed plastic ring construction which presents a smooth finished appearance which may be very readily and cheaply produced and is adapted to a multiplicity of uses such as the production of ornamental chains and the attachment of articles to one another.

A further object of my invention is a provision of a plastic ring or loop for use in permanently connecting hotel key tags to room keys and which may be very rapidly and conveniently applied in connecting the articles and readily permanently sealed. At the same time such links must be of such construction that they may be not only readily applied, but readily removed in order that advertising indicia or the room number may be changed as desired. In accordance with my invention, I am providing a ring which may be very readily applied and which, when severed in any point assumes a position such that it may be very readily removed from the key and tag.

In the accompanying drawings wherein for the purpose of illustration, I have shown various steps in the method I employ, and various forms of rings or loops constructed in accordance with my invention:

Fig. l is a side elevation greatly enlarged showing the first step in the method of constructing the ring;

Fig. 2 illustrates a typical ring prior to permanent closure thereof;

Fig. 3 illustrates the ring of Fig. 2 in its closed position;

Fig. 4 is a perspective view illustrating the method of permanently sealing the joint between the ends of the ring;

Fig. 5 illustrates a modified construction of the type of ring illustrated in Fig. 2;

Fig. 6 illustrates a closed ring of the type shown i F g- 5;

Fig. 7 illustrates a type of ring in which the finished ring is under circumferential tension instead of compression as is the case of the ring in Figures 2 to 6 inclusive;

Fig. 8 illustrates a closed ring of the type shown in Fig. 7;

Fig. 9 illustrates a further type of joint usable in the compression typ ring;

Fig. 10 illustrates a completed ring in use in attaching a key to a key tag; and

Fig. 11 is a typical transverse sectional View through a completed joint.

In accordance with my invention, an extruded resilient plastic is helically coiled about a, mandrel Ill and set in this position. While the use of a circular mandrel has been indicated, this is employed as an illustration since obviously the loops may be circular, ovate, or any other desired form. After the plastic is set, the helical coil is severed into individual segments, these links preferably being each either more or less than 360 in extent. The ends of the individual helical loops ll thus produced are provided upon their opposite sides or outer faces with mating faces l2 each including angularly related areas which, by movement of the loop ends past each other in a direction generally normal to the plane of the loop, may be brought into interlocking engagement with each other and said mating faces will maintain the link ends against separation in directions both circumferential to and normal to the plane of the link.

In the form illustrated in Fig. 2, the mating surfaces l2 comprise a, transverse shoulder l3 and a longitudinally directed sloping face extending between the inner edge of this transverse shoulder and the end of the segment, the slope of this face being such that the tendency of the ends of theloop to displace transversely of the plane of the ring to the position shown in Fig. 3 will merely serve to cause the-link ends to more firmly engage with one another in the direction circumferential to the link as well as in a direction normal thereto. Additionally, since the ring illustrated in these illustrations is a segment of more than 360, the loop will be under compression when the ends are assembled, which compression tends to seat the shoulders l3 firmly against the confronting ends of the segment. The result is that when the ends of the loop have been joined, the resiliency of the material of the loop will maintain their engagement and the loop can be easily handled during the final securing which may be affected as illustrated in Fig. 4 by placing on the surface of the loop at the joint a drop S of solvent of the plastic. Such solvents are usually highly volatile and will penetrate into the crevices of the joint and will form a fusion weld over the joint and in most cases entirely therethrough.

The structure of Figures 2 to 6 and 9 may be modified as illustrated in Figures '7 and 8, in which the segment Ila is less than 360 and the mating faces each comprise a dent l5 and notch [6 for the reception of the dent of the other of the mating faces. While in the examples given above, the segments employed in formation of the loop are all other than 360", it will be understood that it is readily possible to construct such a. loop from a segment of exactly 360 if this is desired.

It will be obvious that such a ring in its completed form is under internal stress in directions both circumferential and normal thereto. In the case of a structure shown in Figures 2 to 6 and 9 inclusive, the loop is under circumferential compression while in the structure of Figures 7 and 8 the ring is under tensio and in all cases the loop is under compression in a direction normal to the plane thereof. The result is that if the loop is severed at any point the ends thereof will immediately separate thereby facilitating the separation of any two articles which may be connected thereby.

Since the various constructions illustrated are obviously capable of modifications, I do not wish to be understood as limiting myself to the particular constructions hereinbefore mentioned except as hereinafter claimed.

I claim:

1. The method of constructing permanently closed plastic loops consisting in forming a hellcal segment of other than 360 from a resilient plastic, forming the outer faces of the ends of the segment with mating angular interlocking surfaces which surfaces, when said ends are brought into alignment with one another are, through the resiliency of the segment, forcibly and interlockingly engaged with one another to resist separation thereof in directions both circumferentially of and normal to the plane of the loop, moving said loop ends past one another in a direction generally normal to the plane of the loop to interlockingly engage said mating surfaces with the ends of the loop in alignment with each other and. applying a solvent of the plastic to the surface of the loop at the joint thus formed.

2. The method of claim 1 wherein the segment is more than 360.

3. The method of claim 1 wherein the segment is less than 360.

4. The method of constructing permanently closed plastic loops consisting in forming a hellcal segment from a resilient plastic, forming the outer faces of the ends of the segment with mating angular interlocking surfaces which,

when the ends of the loop are brought into alignment with one another are, through the resiliency of the segment, forcibly and interlockingly engaged with one another to resist separation thereof in directions both circumferentially of and normal to the plane of the loop, moving said loop ends past one another in a direction generally normal to the plane of the loop to interlockin iy engage said mating surfaces with the ends of the loop in alignment with each other and applying a solvent of the plastic to the surface of the loop at the joint thus formed.

5. The method of claim 4 wherein the loop when the ends are joined is under circumferential compression.

6. The method of claim 4 wherein the loop when the ends are joined is under circumferential tension.

7; A permanently closed loop of resilient plastic which is internally stressed in directions both oircumferentially of the loop and normal to the plane thereof, said loop including a joint area comprising angularly related faces held in engagement with one another by the internal stresses of the loop, at least the external portions of said joint surfaces being fused to one another.

GEORGE J. EVAL'I.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

